GPUTexture: Add support for samplers

This just add back the support.
This commit also includes a bit of cleanup.

# Conflicts:
#	source/blender/gpu/GPU_texture.h

source/blender/editors/interface/interface_icons.c

@@ -1566,8 +1566,7 @@ static void icon_draw_cache_texture_flush_ex(GPUTexture *texture,
   const int img_binding = GPU_shader_get_texture_binding(shader, "image");
   const int data_loc = GPU_shader_get_uniform(shader, "calls_data");
 
-  GPU_texture_bind(texture, img_binding);
+  GPU_texture_bind_ex(texture, GPU_SAMPLER_ICON, img_binding, false);
-  GPU_sampler_icon_bind(img_binding);
   GPU_shader_uniform_vector(
       shader, data_loc, 4, ICON_DRAW_CACHE_SIZE * 3, (float *)texture_draw_calls->drawcall_cache);
 
@@ -1718,8 +1717,7 @@ static void icon_draw_texture(float x,
   GPU_shader_uniform_vector(shader, rect_tex_loc, 4, 1, (float[4]){x1, y1, x2, y2});
   GPU_shader_uniform_vector(shader, rect_geom_loc, 4, 1, (float[4]){x, y, x + w, y + h});
 
-  GPU_texture_bind(texture, img_binding);
+  GPU_texture_bind_ex(texture, GPU_SAMPLER_ICON, img_binding, false);
-  GPU_sampler_icon_bind(img_binding);
 
   GPUBatch *quad = GPU_batch_preset_quad();
   GPU_batch_set_shader(quad, shader);

source/blender/gpu/GPU_texture.h

@@ -66,11 +66,7 @@ ENUM_OPERATORS(eGPUSamplerState)
 extern "C" {
 #endif
 
-#define GPU_SAMPLER_DEFAULT GPU_SAMPLER_FILTER
+void GPU_samplers_update(void);
-#define GPU_SAMPLER_REPEAT (GPU_SAMPLER_REPEAT_S | GPU_SAMPLER_REPEAT_T | GPU_SAMPLER_REPEAT_R)
-
-void GPU_samplers_init(void);
-void GPU_samplers_free(void);
 
 /* GPU Texture
  * - always returns unsigned char RGBA textures
@@ -294,8 +290,6 @@ int GPU_texture_opengl_bindcode(const GPUTexture *tex);
 
 void GPU_texture_get_mipmap_size(GPUTexture *tex, int lvl, int *size);
 
-void GPU_sampler_icon_bind(int unit);
-
 #ifdef __cplusplus
 }
 #endif

source/blender/gpu/intern/gpu_backend.hh

@@ -43,6 +43,8 @@ class GPUBackend {
 
   static GPUBackend *get(void);
 
+  virtual void samplers_update(void) = 0;
+
   virtual GPUContext *context_alloc(void *ghost_window) = 0;
 
   virtual Batch *batch_alloc(void) = 0;

source/blender/gpu/intern/gpu_extensions.cc

@@ -386,13 +386,11 @@ void gpu_extensions_init(void)
   }
 
   GPU_invalid_tex_init();
-  GPU_samplers_init();
 }
 
 void gpu_extensions_exit(void)
 {
   GPU_invalid_tex_free();
-  GPU_samplers_free();
 }
 
 bool GPU_mem_stats_supported(void)

source/blender/gpu/intern/gpu_texture.cc

@@ -482,6 +482,7 @@ void GPU_texture_bind_ex(GPUTexture *tex_,
                          const bool UNUSED(set_number))
 {
   Texture *tex = reinterpret_cast<Texture *>(tex_);
+  state = (state >= GPU_SAMPLER_MAX) ? tex->sampler_state : state;
   GPU_context_active_get()->state_manager->texture_bind(tex, state, unit);
 }
 
@@ -717,19 +718,10 @@ void GPU_texture_get_mipmap_size(GPUTexture *tex, int lvl, int *r_size)
  * Override texture sampler state for one sampler unit only.
  * \{ */
 
-void GPU_samplers_init(void)
+/* Update user defined sampler states. */
+void GPU_samplers_update(void)
 {
-  /* TODO(fclem) port samplers to GLTextures. */
+  GPUBackend::get()->samplers_update();
-}
-
-void GPU_sampler_icon_bind(int UNUSED(unit))
-{
-  /* TODO(fclem) port samplers to GLTextures. */
-}
-
-void GPU_samplers_free(void)
-{
-  /* TODO(fclem) port samplers to GLTextures. */
 }
 
 /** \} */

source/blender/gpu/opengl/gl_backend.hh

@@ -43,11 +43,25 @@ class GLBackend : public GPUBackend {
   GLSharedOrphanLists shared_orphan_list_;
 
  public:
+  GLBackend()
+  {
+    GLTexture::samplers_init();
+  }
+  ~GLBackend()
+  {
+    GLTexture::samplers_free();
+  }
+
   static GLBackend *get(void)
   {
     return static_cast<GLBackend *>(GPUBackend::get());
   }
 
+  void samplers_update(void) override
+  {
+    GLTexture::samplers_update();
+  };
+
   GPUContext *context_alloc(void *ghost_window)
   {
     return new GLContext(ghost_window, shared_orphan_list_);

source/blender/gpu/opengl/gl_state.cc

@@ -427,13 +427,13 @@ void GLStateManager::set_blend(const eGPUBlend value)
 /** \name Texture state managment
  * \{ */
 
-void GLStateManager::texture_bind(Texture *tex_, eGPUSamplerState sampler, int unit)
+void GLStateManager::texture_bind(Texture *tex_, eGPUSamplerState sampler_type, int unit)
 {
   BLI_assert(unit < GPU_max_textures());
   GLTexture *tex = static_cast<GLTexture *>(tex_);
   targets_[unit] = tex->target_;
   textures_[unit] = tex->tex_id_;
-  samplers_[unit] = sampler;
+  samplers_[unit] = GLTexture::samplers_[sampler_type];
   tex->is_bound_ = true;
   dirty_texture_binds_ |= 1 << unit;
 }
@@ -462,6 +462,7 @@ void GLStateManager::texture_unbind(Texture *tex_)
   for (int i = 0; i < ARRAY_SIZE(textures_); i++) {
     if (textures_[i] == tex_id) {
       textures_[i] = 0;
+      samplers_[i] = 0;
       dirty_texture_binds_ |= 1 << i;
     }
   }
@@ -473,6 +474,7 @@ void GLStateManager::texture_unbind_all(void)
   for (int i = 0; i < ARRAY_SIZE(textures_); i++) {
     if (textures_[i] != 0) {
       textures_[i] = 0;
+      samplers_[i] = 0;
       dirty_texture_binds_ |= 1 << i;
     }
   }
@@ -494,7 +496,7 @@ void GLStateManager::texture_bind_apply(void)
       if (dirty_bind & 1) {
         glActiveTexture(GL_TEXTURE0 + unit);
         glBindTexture(targets_[unit], textures_[unit]);
-        // glBindSampler(unit, samplers_[unit]);
+        glBindSampler(unit, samplers_[unit]);
       }
     }
     dirty_texture_binds_ = 0;

source/blender/gpu/opengl/gl_texture.cc

@@ -23,6 +23,8 @@
 
 #include "BKE_global.h"
 
+#include "DNA_userdef_types.h"
+
 #include "GPU_extensions.h"
 #include "GPU_framebuffer.h"
 
@@ -424,6 +426,77 @@ struct GPUFrameBuffer *GLTexture::framebuffer_get(void)
 
 /** \} */
 
+/* -------------------------------------------------------------------- */
+/** \name Sampler objects
+ * \{ */
+
+GLuint GLTexture::samplers_[GPU_SAMPLER_MAX] = {0};
+
+void GLTexture::samplers_init(void)
+{
+  glGenSamplers(GPU_SAMPLER_MAX, samplers_);
+  for (int i = 0; i <= GPU_SAMPLER_ICON - 1; i++) {
+    eGPUSamplerState state = static_cast<eGPUSamplerState>(i);
+    GLenum clamp_type = (state & GPU_SAMPLER_CLAMP_BORDER) ? GL_CLAMP_TO_BORDER : GL_CLAMP_TO_EDGE;
+    GLenum wrap_s = (state & GPU_SAMPLER_REPEAT_S) ? GL_REPEAT : clamp_type;
+    GLenum wrap_t = (state & GPU_SAMPLER_REPEAT_T) ? GL_REPEAT : clamp_type;
+    GLenum wrap_r = (state & GPU_SAMPLER_REPEAT_R) ? GL_REPEAT : clamp_type;
+    GLenum mag_filter = (state & GPU_SAMPLER_FILTER) ? GL_LINEAR : GL_NEAREST;
+    GLenum min_filter = (state & GPU_SAMPLER_FILTER) ?
+                            ((state & GPU_SAMPLER_MIPMAP) ? GL_LINEAR_MIPMAP_LINEAR : GL_LINEAR) :
+                            ((state & GPU_SAMPLER_MIPMAP) ? GL_NEAREST_MIPMAP_LINEAR : GL_NEAREST);
+    GLenum compare_mode = (state & GPU_SAMPLER_COMPARE) ? GL_COMPARE_REF_TO_TEXTURE : GL_NONE;
+
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_WRAP_S, wrap_s);
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_WRAP_T, wrap_t);
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_WRAP_R, wrap_r);
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_MIN_FILTER, min_filter);
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_MAG_FILTER, mag_filter);
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_COMPARE_MODE, compare_mode);
+    glSamplerParameteri(samplers_[i], GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL);
+
+    /** Other states are left to default:
+     * - GL_TEXTURE_BORDER_COLOR is {0, 0, 0, 0}.
+     * - GL_TEXTURE_MIN_LOD is -1000.
+     * - GL_TEXTURE_MAX_LOD is 1000.
+     * - GL_TEXTURE_LOD_BIAS is 0.0f.
+     **/
+  }
+  samplers_update();
+
+  /* Custom sampler for icons. */
+  GLuint icon_sampler = samplers_[GPU_SAMPLER_ICON];
+  glSamplerParameteri(icon_sampler, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
+  glSamplerParameteri(icon_sampler, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+  glSamplerParameterf(icon_sampler, GL_TEXTURE_LOD_BIAS, -0.5f);
+}
+
+void GLTexture::samplers_update(void)
+{
+  if (!GLEW_EXT_texture_filter_anisotropic) {
+    return;
+  }
+
+  float max_anisotropy = 1.0f;
+  glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &max_anisotropy);
+
+  float aniso_filter = max_ff(max_anisotropy, U.anisotropic_filter);
+
+  for (int i = 0; i <= GPU_SAMPLER_ICON - 1; i++) {
+    eGPUSamplerState state = static_cast<eGPUSamplerState>(i);
+    if (state & GPU_SAMPLER_MIPMAP) {
+      glSamplerParameterf(samplers_[i], GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso_filter);
+    }
+  }
+}
+
+void GLTexture::samplers_free(void)
+{
+  glDeleteSamplers(GPU_SAMPLER_MAX, samplers_);
+}
+
+/** \} */
+
 /* TODO(fclem) Legacy. Should be removed at some point. */
 uint GLTexture::gl_bindcode_get(void) const
 {

source/blender/gpu/opengl/gl_texture.hh

@@ -58,6 +58,9 @@ class GLTexture : public Texture {
   friend class GLStateManager;
 
  private:
+  /** All samplers states. */
+  static GLuint samplers_[GPU_SAMPLER_MAX];
+
   /** Target to bind the texture to (GL_TEXTURE_1D, GL_TEXTURE_2D, etc...)*/
   GLenum target_ = -1;
   /** opengl identifier for texture. */
@@ -85,6 +88,10 @@ class GLTexture : public Texture {
   /* TODO(fclem) Legacy. Should be removed at some point. */
   uint gl_bindcode_get(void) const override;
 
+  static void samplers_init(void);
+  static void samplers_free(void);
+  static void samplers_update(void);
+
  protected:
   bool init_internal(void) override;
   bool init_internal(GPUVertBuf *vbo) override;

source/blender/makesrna/intern/rna_userdef.c

@@ -364,8 +364,7 @@ static void rna_userdef_load_ui_update(Main *UNUSED(bmain), Scene *UNUSED(scene)
 
 static void rna_userdef_anisotropic_update(Main *bmain, Scene *scene, PointerRNA *ptr)
 {
-  GPU_samplers_free();
+  GPU_samplers_update();
-  GPU_samplers_init();
   rna_userdef_update(bmain, scene, ptr);
 }